Hα, [S II] 6731  Å  and [N II] 6548  Å  PV diagrams obtained from the STIS position 2 observations. The PV diagrams are shown with a logarithmic grey scales, with the fluxes given in units of erg cm^-2 s^-1 Å^-1 arcsec^-2 by the bars above each plot. Linear contours have been superposed to the [S II] PV map (white contours). The radial velocities were corrected by the systemic velocity (~− 21 km s^-1). The ordinate gives position along the slit. The zero position corresponds to the point along the slit closest to the central source. Spectral features are labeled. The vertical arrows aid to identify the redshifted component (see text).